Quantitative MRS: comparison of time domain and time domain frequency domain methods using a novel test procedure

Elster, Clemens; Link, Alfred; Schubert, Florian; Seifert, F.; Walzel, Monika; Rinneberg, H.

doi:10.1016/s0730-725x(00)00140-5

Cited by 17 publications

(15 citation statements)

References 12 publications

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“…40,46 This method involves automatic correction for frequency shifts caused by involuntary subject motion and system instabilities, inclusion of phantom basis spectra and prior knowledge into the fit, and background estimation. In the present spectra, the resonances of total choline (tCho, total creatine (tCr), NAA, and glutamate and glutamine resonances were fitted by inclusion of phantom spectra (0.1 M metabolite at pH 7.2 and 37 1C in spherical bottles) for the latter three, and imposing constant frequency differences for glutamate, glutamine and NAA, and equal line widths as prior knowledge.…”

Section: Hormonal Measurementsmentioning

confidence: 99%

Glutamate as a spectroscopic marker of hippocampal structural plasticity is elevated in long-term euthymic bipolar patients on chronic lithium therapy and correlates inversely with diurnal cortisol

et al. 2008

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While an excess of glucocorticoids is associated with hippocampal pathology in mood disorders, lithium exerts robust neuroprotective and neurotrophic effects. Here, 21 stably remitted bipolar I patients who had been on chronic lithium maintenance therapy, on average, for more than a decade, and 19 carefully matched healthy controls were studied using 3 T 1 Hmagnetic resonance spectroscopy of left and right hippocampus. Salivary cortisol samples were obtained to assess activity of the hypothalamus-pituitary-adrenal system. Absolute concentrations of N-acetylaspartate (NAA), choline-containing compounds and total creatine were similar in euthymic bipolar patients and healthy controls. Hippocampal glutamate concentrations were significantly increased as an effect of patient status (patients > controls) and laterality (left hippocampus > right hippocampus). Hippocampal glutamate content (Glu) was strongly correlated with NAA. Across groups and within the patient group, diurnal saliva cortisol levels showed a significant inverse relationship with both Glu and NAA. Taken together, these results add to the concept of bipolar disorder as an illness involving disturbed hippocampal structural plasticity under the opposing influences of lithium and glucocorticoids.

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Section: Hormonal Measurementsmentioning

confidence: 99%

Glutamate as a spectroscopic marker of hippocampal structural plasticity is elevated in long-term euthymic bipolar patients on chronic lithium therapy and correlates inversely with diurnal cortisol

et al. 2008

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“…Peak finding and fitting routines are then applied to estimate similar parameters for the metabolites of interest. Several studies have been conducted to compare different time and frequency domain-based approaches for accurate quantification of 13 C spectra from liver (19), 31 P spectra from rat tumors (20) and 1 H spectra from blood plasma (21), brain (22)(23)(24) and brain simulations (25).…”

Section: Introductionmentioning

confidence: 99%

Quantification of prostate MRSI data by model‐based time domain fitting and frequency domain analysis

Pels

Öztürk-Işık²,

Swanson

et al. 2006

NMR in Biomedicine

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This paper compares two spectral processing methods for obtaining quantitative measures from in vivo prostate spectra, evaluates their effectiveness, and discusses the necessary modifications for accurate results. A frequency domain analysis (FDA) method based on peak integration was compared with a time domain fitting (TDF) method, a model-based nonlinear least squares fitting algorithm. The accuracy of both methods at estimating the choline + creatine + polyamines to citrate ratio (CCP:C) was tested using Monte Carlo simulations, empirical phantom MRSI data and in vivo MRSI data. The paper discusses the different approaches employed to achieve the quantification of the overlapping choline, creatine and polyamine resonances. Monte Carlo simulations showed induced biases on the estimated CCP:C ratios. Both methods were successful in identifying tumor tissue, provided that the CCP:C ratio was greater than a given (normal) threshold. Both methods predicted the same voxel condition in 94% of the in vivo voxels (68 out of 72). Both TDF and FDA methods had the ability to identify malignant voxels in an artifact-free case study using the estimated CCP:C ratio. Comparing the ratios estimated by the TDF and the FDA, the methods predicted the same spectrum type in 17 out of 18 voxels of the in vivo case study (94.4%).

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“…those derived analytically such as TDFDfit) has been given . The parametric description is more flexible, easily allowing for changes such as echo time, but takes longer to compute (Elster et al, 2000).…”

Section: Fitting To Estimate Peak Areamentioning

confidence: 99%

Spectroscopy: ¹ H Metabolite Concentrations

Tofts

Waldman

2003

Quantitative MRI of the Brain

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Quantitative MRS: comparison of time domain and time domain frequency domain methods using a novel test procedure

Cited by 17 publications

References 12 publications

Glutamate as a spectroscopic marker of hippocampal structural plasticity is elevated in long-term euthymic bipolar patients on chronic lithium therapy and correlates inversely with diurnal cortisol

Glutamate as a spectroscopic marker of hippocampal structural plasticity is elevated in long-term euthymic bipolar patients on chronic lithium therapy and correlates inversely with diurnal cortisol

Quantification of prostate MRSI data by model‐based time domain fitting and frequency domain analysis

Spectroscopy: ¹ H Metabolite Concentrations

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Quantitative MRS: comparison of time domain and time domain frequency domain methods using a novel test procedure

Cited by 17 publications

References 12 publications

Glutamate as a spectroscopic marker of hippocampal structural plasticity is elevated in long-term euthymic bipolar patients on chronic lithium therapy and correlates inversely with diurnal cortisol

Glutamate as a spectroscopic marker of hippocampal structural plasticity is elevated in long-term euthymic bipolar patients on chronic lithium therapy and correlates inversely with diurnal cortisol

Quantification of prostate MRSI data by model‐based time domain fitting and frequency domain analysis

Spectroscopy: 1 H Metabolite Concentrations

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Spectroscopy: ¹ H Metabolite Concentrations